Lubricating oil



Patented Oct. 7, 1941 UNITED-STATES PATENT OFFICE LUBRICATING on.

Bert H. Lincoln and Gordon D. Byrkit, Ponca City, Okla., assignors to Continental Oil Company, Ponca City, Okla., a corporation of Delaware No Drawing.

Application May 24, 1939,

Serial No. 275,488

6 Claims.

als. These comparatively soft metals are cor-- roded readily by oils which have been used for a short time in the engine. One method of overcoming this difficulty would be to use more resistant bearing compositions, and another would be to use an oil which does not develop these corrosive materials during use. Still another method would be to use a lubricant containing a material which would react with and render inert the corrosive products as rapidly as they areformed. Our invention is not concerned with the-first method but with the other two possibil ities. Various addends have been proposed to be added to lubricants for the purpose of inhibiting the formation of corrosive materials during use. These may be called antioxidants, since they increase the time of use before rapid oxidation begins to .occur and also decrease the rate of oxidation after it has started. Various addends have also been proposed to be added to lubricants for the purpose of reacting with such corrosive materials, as may in time be formed, and removing them from the oil so that they are unable to corrode the parts being lubricated. These may be called precipitants. The present invention proposed addends combining these two capabilities in the same molecule to give an unexpectedly superior activity in both respects over what would be predicted from a simply additive effect.

Certain compounds are adsorbed or absorbed by metals forming tenacious films at the surface of metals which are able to stand high pressures. X-ray diffraction methods have shown that compoundscontaining highly polar molecules, that is, molecules of unsymmetrical character containing an atom or group of atoms exhibiting a secondary or residual valence, tend to .produce regimentation of the molecules of hydrocarbon oil when added thereto. A metal immersed in a strongly polar compound will show a film of the compound in which there is a regimentation of molecules oriented with respect to the surface of the metal by which they are adsorbed or absorbed.

One object of our invention is to provide a substantially noncorrosive lubricant for use with the newer, easily corroded bearing compositions. It is to be noted, however, that the improved lubricant here described is advantageously employed with all types of bearings, since it is less corrosive during use with any of the metals commonly encountered in practice.

Another object of the invention is to provide a lubricant inhibited against oxidation during use.

A further object is to provide a lubricant containing an addend capable of reacting with or otherwise rendering inert such corrosive products as may be formed during extended use.

Other objects of the invention will appear in the following description.

Our invention consists of the addition to lubricants of all kinds of salts or soaps of sulfurbearing acids. These salts may be of diverse types and both the anionic, and cationic parts of these soaps may be varied. Thus the cations may be purely organic orpurely metallic or organo-metallic. The sulfur-bearing acidic radicals may contain sulfur in various forms. They may be thio-ethers, mercaptans, sulfones, heterocyclic sulfur rings, or sulfurized unsaturated acids or sulfur-chloride treated unsaturated acids and the like. In the following examples, any of the cations may be used with any of the anions to form these soaps, and it is to be understood that each of these combinations when blended, suspended, or otherwise mixed with a lubricant is an example of the invention.

I. Anions A. Sulfurized acids Sulfurized oleic acid Sulfurized linoleic acids Sulfurized linolenic acids Sulfurized elaidic acid Sulfurized corn oil acids Sulfurized soy oil acids Sulfurized lard oil acids Sulfurized tung oil acids Suifurized 'abietic acid 10. Sulfurized cholic acid 11. Sulfurized naphthenic acids B. Phosphorus sulfide treated acids (con-- taining phosphorus and sulfur) 1. Phosphorus pentasulfide treated corn oil acids 2. Phosphorus trisulfide treated corn oil acids 3. Phosphorus pentasuiilde treated soy oil acids 4. Phosphorus pentasulflde treated oleic acid 5. Phosphorus pentasulfide treated linoleic acid C. Sulfur chloride treated acids 1. Sulfur chloride treated oleic acid 2. Sulfur chloride treated linoleic acid 3. Sulfur chloride treated linolenic acids 4. Sulfur chloride treated elaidic acid 5. Sulfur chloride treated corn oil acids 6. Sulfur chloride treated soy oil acids 7. Sulfur chloride treated lard oil acids 8. Sulfur chloride treated tung oil acids 9. Sulfur chloride treated abietic acid 10. Sulfur chloride treated cholic acid 11. Sulfur chloride treated naphthenic acids D. Sulfur-bearing acids of known constitution 1. Mercapto acids a. Mercapto-stearic acid b. Mercapto-acetic acid 0. Thiophenol 4 carboxylic acid d. Thiophenylacetic acid e. Mercapto-chlorostearic acid 2. Sulfldo acids a. Methylmercapto-s t e ar 1! acid b. Ethylmercaptophenyl acetic acid 0. Amylmercaptobenzene 4 carboxylic acid d. Methylmercapto-c h 110 r ostearic acid 3. Sulfone acids a. Ethylsulfone beta carboxylic acid b Phenylsulfone-d-carboxylic acid 0. Chlorophenylsulfone-Z-carboxylic acid 4. Disulfldo acids a. Ethyldisulfidobenzene 2 carboxylic acid b. Amyldisulfldophenylace tic acid 0. Benzyldisulfidobenzylstearic acid 5. Sulfonic acids a. Benzene suli'onic acid b. Tri isopropylnaphthalene sulfonic acid 0. Chloronaphthalene sulfonic acid d. Amyl sulfonic acid 6. Sulfinic acids a. Benzene sulfinic acid b. n-Butyl sulfinic acid 7. Sulfato acids at. Acid sulfate of 12-hydroxystearic acid b. Acid sulfate of ricinoleic acid 0. Neutral sulfate of 12-hydroxystearic acid 8. Sulfito acids 11. Sulflte of lz-hydroxystearic acid b. Sulflte of ricinoleic acid 9. Xanthates a. Ethylxanthate b. Butylxanthate c. Amylxanthate d. Benzylxanthate II. Cations A. Metallic 1. Group 1 Lithium, sodium, potassium,

rubidium, cesium, copper 2. Group 2 Calcium, strontium, barium, beryllium, magnesium, zinc, cadmium, mercury 3. Group 3 Aluminum, gallium,

thallium 4. Group 4 Titanium. zirconium. tin, lead 5. Group 5 Arsenic, antimony, bismuth 6. Group 6 C h r o m iu m, molybdenum,

tungsten 7. Group 7 Manganese 8. Group 8 Iron, cobalt, nickel B. Organo-metallic These organo-metallic soaps may have, in the organo-metallic cation, an organic radical or radicals of the aliphatic or carbocyclic or heterocyclic series. The metallic element of the compound may be any one of a number of which the following are representative. For convenience, we shall list them in accordance with their occurrence in the periodic table:

Group II Magnesium Zinc Cadmium Mercury Group III Boron Aluminum Thallium Group IV Silicon Tin Lead Group V Arsenic Bismuth Antimony Group VI Tellurium Selenium Some of the organo-metallic radicals which may act as cations in forming the soaps to be used are:

Group H Phenylmagnesium Propyl magnesium Methylzinc Cresylzinc Xylycadmium iso-Amylcadmium Butylmercury Mesitylmercury indium,

a,eo7,7oo 3 v Nitrophenylmercury Naphthylmercur'y Group III Phenylboron (II) Diphenylboron (I) o-xvlylboron (II)- Dipropylaluminum Diethylthallium Diphenylthallium Di-p-tolylthallium Group IV Triphenylsilicon Triphenylgermanium Di-isoamyltin Di-alpha-naphthyltin Diphenyltin Ethylphenyltin Iso-propyitin Triethyltin Triphenyltin Di-isobutyllead Diethyllead Diphenyllead Triphenyllead Group V Ethylarsenic Diphenylantimony Di-alphanaphthylbismuth Diphenylbismuth Group VI Phenyltellurium Diphenyltellurium Triphenyltellurium Phenylselenium The soaps derived from these organo-metallic radicals may contain in the organic radical or attached to the metal or in the anion of the soap an additional element or combination of elements including the halogens, sulfur, phosphorus, nitrogen, or oxygen.

Some of the combinations of the cations with the anions are listed below, but it is obvious that all the possible combinations serve as examples of the invention when admixed with lubricating oils or greases:

1. Sodium-salts of sulfurized corn oil acids 2. Aluminum salts of sulfurized beta fat 3. Calcium salts of sulfur. chloride treated linolcic acid 4. lead salts of sulfur-chloride treated oleic acid 5. Stannous salts of sulfurized corn oil acids 6. Stannic salts of sulfurized corn oil acids '7. Ammonium salts of sulfurized soy oil acids 8.'Triamylammonium salts of methylmercapto stearic acid 9. Triphenyltin salts of sulfurized corn oil acids 10. Triethyltin salts of ethyl sulfone-beta-carboxylic acid 11. Diethylthallium salts of sulfurized corn oil l9. Triethyltin mercaptostearate 20. 'Iriphenyltin mercaptostearate 21. Triphenyltin salts of sulfur chloride treated corn oil acids 22. Diphenyllead di (mercaptostearate) 23. Ethy-iarsenic salts of phenylsulfone-i-carboxylic acid 24. Diphenylantimony benzenesulfonate 25. Diphenyltellurium di (mercaptostearate) '26. Triphenyltin amyl xanthate 27. Triphenyltin salt of the reaction product of benzyl disulflde, dichlorostear'ie acid and aluminum chloride 28. Di-isobutyl-lead dixanthylstearic acid methyl quantities ranging from 0.1 per cent to about 10.0

per cent must be added. As an anticorrosive agent and/or an antisludging agent, much smaller amounts must be used, ranging from approximately 0.001 to 0.1 per cent. The action of the organo-metallic compounds is specific but difficult to understand. These compounds may be added to any type of hydrocarbon lubricants. but show an unusual value in highly refined and solvent -treated' lubricants. I

The lubricating oil portion of the blends of our invention may be so-called mineral or hydrocarbon oils or may consist of wholly or contain only in part certain fatty oils including corn oil, soybean oil, lard oil, and the like. The blends may contain voltolized oils or synthetic oils of lubricating viscosity. Soap thickened or otherwise thickened oils used as greases may be employed. Addends for other purposes such as pour point depressors may be present,

These compounds have varying degrees of solubility in hydrocarbon oil. In some cases. it is necessary to use a solvent for the compound or to form colloidal suspensions of the compound in oil. v

The film strength and oxidation characteristics of solid and semisolid greases may be im-' proved by the addition of small amounts of my metallic soaps thereto. The chemical purity for use as extreme pressure addition agents is not critical. All that is important is that no corrosive contaminants be'present. Mixtures of a number of these compounds may be employed.

It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope .of our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is therefore to be understood that our invention is not to be limited to the specific details shown and described.

Having thus described our invention, we claim: 1. A lubricant comprising in combination a major proportion of an oil of lubricating viscosity and a minor proportion of an organo-metallic salt of a sulfur-bearing organic acid.

2. A lubricant comprising in combination a major proportion of an oil of lubricating viscosity and a minor proportion of an organo-metallic salt of a sulfurized organic acid.

3. A lubricant comprising in combination a major proportion of an oil of lubricating viscosity and a minor proportion of an organo-metallic salt of a sulfur-chloride treated organic acid.

4. A lubricant comprising in combination a major proportion 01 an oil of lubricating viscosity and a minor proportion of triphenyltin salt of sulfurized corn oil acids.

A lubricant comprising in combination a major proportion of an oil of lubricating viscosity and a minor proportion. of diphenylboron mercaptostearate.

6. A lubricant comprising in combination a major proportion of an oil of lubricating viscosity and a minor proportion of triethy-ltin salt of sul- 10 furized lard oil acids.

BERT H. LINCOLN. GORDON D. BYRKIT 

